This invention relates generally to a support assembly for a frame or rail assembly to connect a headboard and a footboard and, ultimately to support a mattress and box spring, and, more particularly, to an improved universal cross member support for a bed frame or bed rails.
Bed frames or bed rails are widely used to provide a support for the box spring and mattress and are of a relatively straightforward construction comprising a rectangular or square frame. In the case of bed rails, there are normally side rails that are wooden, rolled formed metal or angle iron and which connect to a headboard and a footboard. The side rails, the headboard and the footboard are interconnected so that the overall unit may be readily assembled and the unit is of predetermined dimensions so as to accept a standard box spring that is seated upon the frame.
Originally, the side rails would support laterally placed wooden bed slats that would cross the bed frame and support the box spring. Such wooden slats were strong enough to provide the necessary support to the box spring, however, they were generally troublesome, somewhat weak and were cumbersome to install and maintain in place, and required screws for assembly, particularly when moving the bed from one location to another. It was necessary to cut each slat to the particular width or space between the bed rails and the construction relied on the weight of the box spring and mattress to keep the slats in place.
As an alternate, therefore, there are currently used, one or more cross members that are constructed of steel angle iron and normally are L-shaped and are placed laterally across the frame spanning the side rails. Thus, as an improvement, the steel cross members replaced the wooden slats which made the consequent set up, construction and transportability considerable easier and the overall construction stronger. In addition, metal supports have also been used in conjunction with the wooden slats. Obviously, the steel cross members could be constructed of very heavy gauge steel so that adequate support could be provided for the box spring and mattress, however, the use of heavy gauge steel increases the cost of the cross member and additionally, adds to the overall weight of the structure. Therefore, although constructed of steel, the present cross members alone are not sufficient to provide the necessary amount of support for the box spring and mattress.
Thus, virtually all bedding manufacturers require the use of a rigid center support for the cross member, whether the construction is a bed frame or bed rails in order to insure the structural integrity of the box spring to prevent damage to that component. The use of such a rigid center support virtually precludes the use of a typical wooden slat or typical angle iron cross member without the use of a leg assembly that actually contacts the floor for the needed support to the cross member. Accordingly to solve the problem of a lack of adequate support, manufacturers universally turned to the use of a leg that relied on contact with the floor to add that support. An example of such solutions is shown in U.S. Pat. No. 5,502,852 of Fredman et al; U.S. Pat. No. 5,815,860 of Mitchell and U.S. Pat. No. 5,894,614 of Stroud.
It therefore became necessary to add a glide or glides to the leg of the steel cross member that spanned between the side rails to provide sufficient support to the cross member. The glide is generally affixed to a leg depending downwardly from the cross member and, in turn, the glide contacts the floor with a flat, planar bottom surface so that the cross member is supported on the floor and thus gives crucial support to the box spring and to the other components of the assembled bed. It should be noted, that while the glide is referred to as having a flat, planar bottom surface, that surface is an effective flat surface as the bottom of the glide may have its inner portion displaced upwardly such that the entire bottom surface is not really totally flat and planar. If totally flat, the tolerances would be considerably strict and thus, normally only an effective flat planar surface is formed in the bottom of such glides.
Obviously, with the use of a leg and glide to support the cross member, it is important that the overall length of the glide assembly, that is, the glide and the leg, be fairly precise with respect to the cross member. If the length of the glide assembly is too short, there is inadequate support for the cross member and the cross member will bow downwardly under the weight of the box spring until the necessary contact between the glide and the floor is established. If, on the other hand, the length of the glide assembly is too long, it causes the cross member to bow upwardly. In either case, the result is undesirable and can cause structural damage to the cross member and possibly to the box spring.
It is therefore necessary that the glide assembly be of the proper height and to that end, the glide itself is normally threadedly affixed to the leg so that the glide can be simply rotated by the user to raise and lower the glide to arrive at the proper desired height. The need for the adjustment is paramount in that the headboad and footboard, if there is one, is not a standard industry height above the floor and thus, the height of the frame and the side rails off the floor will differ from bed to bed so that a fixed height glide assembly would not be suitable to fit all beds universally. In addition, the bed may, from time to time, be moved about the room and the glide need to be readjusted due to irregularities in the floor itself to correct for high and low spots of the floor.
A further example of a cross member is shown and described in U.S. Pat. No. 4,080,674 of Fredman where the cross member includes a pair of supporting legs each of which have a vertically adjustable glide to insure that the cross member is adequately supported by the flooring without twisting or misalignment. Again, as explained, the solution is founded upon a reliance upon the floor to adequately support the center member. Other examples of devices or vertically adjustable legs are shown an described in U.S. Pat. No. 5,502,852 of Fredman et al; U.S. Pat. No. 5,815,860 of Mitchell and U.S. Pat. No. 5,894,614 of Stroud, all of which have some means of adjusting the vertical length of a leg so that the overall bed frame can utilize the floor for support.
Typically, therefore, the glide has an upwardly extending threaded stem that mates with a corresponding threaded opening in the leg located in the desired position. The stem itself is generally small in diameter, about one quarter to one half inch diameter, for most applications, and its support in the leg is relatively secure and sufficiently strong for use as a support for the cross member when in place, i.e encountering compressive forces, however the overall glide assembly is not particularly strong when subjected to side forces and opened to the full extension of height.
Accordingly, when the headboard and footboard are moved from one location to another, such as for cleaning under the bed, and particularly when the box spring and the mattress are in position upon the bed frame, the glide drags on the floor as the bed is moved. Where the floor is covered, for example, with carpeting, the dragging causes twisting of the glide assembly and can easily lead to a breaking of the leg from the cross member and/or severe damage to the box spring.
Too, the cross member is, as indicated, generally a steel L-shaped member and is easily twisted through the influence of a bending of the glide member so that damage to the cross member is a good possibility. Added to that weakness, is the fact that many cross members are coupled together at the center point between the two side rails, that is, the cross member is generally extended in two sections inwardly from the side rails and is coupled together at or near the center of the span between the side rails by some clamp or other coupling device to compensate for the varying widths of the headboards and footboards.
Thus, the center of the span between the supporting side rails is already a vulnerable spot where the cross member is weak, however, adding to that weakness is the use of a coupling at that center spot where the two individual cross member are joined together by a clamp. In short, the glide assembly that supports the cross member is in a most vulnerable position with respect to being damaged or to damaging the cross member and the box spring by the user moving it from one location to another or by simply having the height adjustment incorrectly set.
Obviously for the user or installer, this is a severe problem as it creates the necessity to obtain another bed rail or support system as the breaking of a leg is generally not repairable since the components are stamped metal parts that are riveted together. It would certainly be advantageous to avoid the problem altogether so that the bed frame is not subject to the breakage problem herein outlined.
Another problem exists in the construction of a cross member in that the actual width or span between the side rails may have a variance and thus there may need to make an adjustment in the length of the cross member to insure that it properly aligns with the particular fitting or bracket in the side rails. The difficulty is particularly significant where the cross member is assembled by fitting into brackets or the like in the side rails as the length must be accurate to make the proper fitting possible. Thus, presently there are many ways to attach the cross members to a side rail that are non-standard devices.
Accordingly, it would be advantageous that the length of the cross member be designed so as to be adjustable to make certain its assembly to the side rails can be made easily and accurately. An attempt at solving that problem is shown in the aforementioned disclosures of U.S. Pat. No. 5,502,852 of Fredman et al; U.S. Pat. No. 5,815,860 of Mitchell and U.S. Pat. No. 5,894,614 of Stroud. However, again, the center of the cross member is already the weakest area of the cross member and the addition of a sliding connection at that point adds to the weakness of the cross member. It would be advantageous to allow the cross member to have a width adjustment without detracting from the overall integrity of that cross member.
In accordance with the present invention, there is provided a cross member that may be used with a bed frame or bed rails and which overcomes the aforedescribed difficulties of current cross members. In the present invention, a cross member is described that is a universal cross member, that is, the cross member can be used in almost all applications where a cross member is needed and can be adapted for use with current bed frames and bed rails as well as to newly manufactured bed frames and rails.
With the universal cross member of the present invention, the need for a support glide or caster to support the cross member is, in almost all instances, eliminated such that the cross member does not require any support that contacts the floor beneath the cross member. Accordingly, the need for some initial setting and constant readjustment of the height of such a support component is eliminated along with the consequent problems associated therewith and previously described. In addition, due to the unique construction of the present universal cross member, the gauge of the steel used can still be a relatively light gauge and not a heavy steel component.
As another feature of the present universal cross member, the length of the universal cross member is adjustable such that the present universal cross member can be adjusted to account for differences in the distance between the bed rails. That length adjustment is provided at the ends of the universal cross member and not in the center area of the universal cross member so that the structural integrity of the universal cross member is not compromised. The length adjustment is provided by the use of slides, generally of a metal material and which has ends that are preferably constructed of an injection molded plastic material i.e. a glass filled nylon composition, and therefore a relatively inexpensive material that can be molded to a variety of configurations.
Accordingly, as will be seen, therefore, the present universal cross member can be used in a wide variety of bed rails and is suitable for any height of the legs of the headboard or other component since there is normally no center support that must be in contact with the floor and additionally, the length is adjustable so that the present universal cross member can be used with differing distances between the side rails.
The universal cross member of the present invention includes a generally straight member, preferably tubular, that is caused to be put in tension such that there is an upward force generally located at the center of the straight member and acting in a direction opposite to the force created by the weight of the box spring, mattress and other items that make up the completed bed so that no contact with the floor is necessary. As such, therefore, the present universal cross member can be used in almost any application and can provide the added strength and rigidity to the bed frame without the problems associated with a support that is in contact with the floor.
The principle of the present invention and its ability to provide support without actual contact with the floor is based upon a support beam that is positioned between two fixed points. When a load is added to the center of the beam acting in a downward direction, the beam will deflect downwardly after a certain amount of weight is added and the deflection will increase as addition load is added to the beam. With the present invention, the use of the tension member is used to reinforce that center and the tension member diverts the force caused by the weight outwardly much closer to the fixed end points of the beam. The diverted force is thus acting on a more supported area because those points are nearer to the fixed end points. In effect, the force acting downwardly in the center of the beam is diverted to other points at or near the ends of the beam and the beam deflection is reduced with the present invention upon imposition of the same load as a normal beam.
As sometimes used herein, the term tension member, as will be seen, is preferably a metal steel strap, however, that tension member may also be referred to as a tension bar and may be a cable, strap, bar, wire or other component, it only being important that the tensile strength of the tension member be sufficient to carry out its intended purpose in accordance with the present invention and must be of a material and of sufficient dimensions so as to provide the required amount of tension on the straight member.
In the present invention, the straight member can be formed in a variety of cross sectional shapes that generally have a symmetrical cross section and preferably in the form of a tubular steel member of a rectangular, preferably square shape. The weight of the box spring, mattress and the like acts downwardly on a surface of the straight member so, to counter that force, a force is exerted against a surface of the straight member on an opposite surface of that straight member and which acts in an opposite direction to the downwardly directed force created by the box spring and other components, thus, acting to counter the downward force with an upwardly directed force. That upward force is applied generally in the vicinity of the center of the straight member.
To create the upward force, a force transmitting means is located in the vicinity of the center of the straight member and a tension bar extends from the force transmitting means to be affixed to the straight member at locations at or near the ends of the straight member. That tension bar may take the form of a steel strap in the preferred embodiment. As will be seen, the force transmitting means may be a solid block of material, i.e. a metal stamping or a casting, or a molded plastic component, it only being important that the force transmitting means transmit the force from the tension bar or strap to the straight member. The tension bar is maintained in tension so as to create the force that acts upwardly on the straight member tending to bow the center of the straight member upwardly and pull the ends of the straight member inwardly and downwardly.
To create that tension, the tension bar is in contact with the force transmitting means and also has its ends affixed to the straight member, preferably at points at or near the ends of the straight member. A tension means may be provided, in one embodiment, that creates tension in the tension bar and which, in turn applies the force to the force transmitting means and thus to the straight member. One such tension means may be a mechanism that actually pulls or stretches the tension bar by applying a force at one or both ends of the tension bar in a direction outwardly from the center of the tension bar, or if more than one tension bar is employed, the pulling or stretching is in a direction outwardly from the point of contact with the force transmitting means. Again, as the tension member is stretched, its tendency is to straighten, however, since the center of the tension bar is displaced a finite distance from the center of the straight member by the force transmitting means, in trying to straighten the tension member, a force is created upwardly against the center of the straight member and the ends of the straight member are pulled inwardly and downwardly tending to create a slight bow in the tubular bar counter to the direction of the weight applied by the box spring, mattress and the like.
In one embodiment, the tension means comprises a flange through which the tension bar passes and the flange is affixed to the ends of the straight member. In that embodiment, the ends of the tension bar are threaded and nuts are affixed on to those threaded ends. Thus, by rotating the nuts on the ends on the tension bar, the tension imposed on that bar can be adjusted at will.
A more preferred means of maintaining tension in the tension bar is to employ a steel strap that is affixed to the straight member at or near the ends thereof and which is initially put in tension and then secured to the straight member so as to keep that tension in the strap. In the more preferred strap, the edges of the metal strap are rolled inwardly so as to add to the strength of the strap itself as well as to eliminate the otherwise relatively sharp edges of the steel strap.
In the preferred embodiment, the straight member is a rolled steel bar of a rectangular cross section and the tension bar is a steel strap that contacts the force transmitting means located at the approximate center of the straight member. The ends of the steel strap are riveted to the rolled steel bar at or near the ends of the bar and the strap is thus maintained in tension. In an ideal construction, straight member has its center portion bowed slightly upwardly in the direction toward the load to be imposed on the straight member as the steel strap is riveted to the straight member. As such, when released from the bowed configuration, the center portion returns to a straightened configuration, thus pulling the ends of the straight member upwardly to inherently create a pulling effect on the tension member to create a tension in that member. The force transmitting means is, as explained, thus simply the application of tension to the steel strap and then affixing the strap to the straight member while retaining the steel strap in tension. In the preferred embodiment, the tension causes just a slight bow in the tubular bar such that its center bows upwardly slightly in the direct of the box spring and, of course, the upward bow is opposite to the direction of the forces exerted downwardly by the box spring and other components of the completed bed.
In an ideal manufacturing process, the tension member may be just taut, that is, there is in reality a zero tension initially on the tension member but that tension is immediately created upon the imposition of a load on the straight member to create the tension when the universal cross member is employed to support a load directed downwardly on the straight member. Unfortunately, it imposes extremely close tolerances on the manufacturing process to create a taut, zero tension in the tension member of a completed universal cross member such that it is more preferable to deliberately create the pre-tension by retaining a slight bowing of the straight member.
In summary, therefore, during the normal, preferred construction of the universal cross member, the tension bar is deliberately put in tension a predetermined amount and which forces a generally centrally located block or spacer upwardly to cause an upward force on the straight member such that the straight member is caused to assume a slightly bowed position.
In the manner described, the use of a additional support or supports for the straight member of the present invention that provide support from the floor to the universal member can be fully eliminated, thus the bed frame can be of any height from the floor, there being a minimum distance from the floor in order to provide the physical space for the universal cross member itself, and no adjustment needed to any support for the universal cross member. Accordingly, while the present invention is suited for most beds for use without any added center support using a floor engaging device, there may be instances where such a center support or even other supports need be added as a supplement. Such instance could occur, as an example, where the bed is a water bed where the normal loading is heavy or where there is simply an unusually heavy load applied to the bed. In such instances a molded plastic support can be provided that also serves to hold a leg. Again, in the preferred embodiment, the molded plastic support can serve to transfer the force from the tension steel strap to the straight member and, at the same time, can serve to contain a leg that can be set to a length so as to reach the floor for the needed support.
In the more preferred embodiment the leg, when used, may be affixed to the molded plastic support so as to be self adjusting, that is, the leg can conveniently be affixed to the molded plastic support by means of a mechanism that allows the user to simply drop the leg by gravity to reach the desired length touching the floor and retained firmly in that position. That automatic vertical leg adjustment is particularly advantageous since no measuring in necessary nor is there any need to rotate and screw in or out each leg to adjust each leg individually. For example with a water bed, there are normally nine legs that are positioned about the underside of the water bed to support the bed from the floor. Therefore, in the installation and set-up of such a bed, it has been necessary for the person carrying out the installation, to individually make a vertical adjustment by screwing down and balancing each of the nine legs to make sure each leg is in the proper contact with the floor. With the present, self vertically adjusting legs, the legs do not require the individual attention and can easily be automatically adjusted for the particular floor by simply releasing the leg to have it drop by gravity to a correct vertical height in proper contact with the floor. The legs therefore automatically lock into the desired position when they reach contact with the floor.
In order to optimize the efficiencies in manufacturing, the molded plastic support may be moved or located at a variety of positions along the length of the straight member as desired by the user and as dictated by the particular load imposed upon the cross member. Additionally, there may be more than one support used and each may be manufactured identically when a leg is utilized or not utilized or whether one or more legs are utilized.
As a further feature of the present invention and the applicability of the universal cross member, an improved means is provided to affix the universal cross member to the side rails, whether such side rails are wooden rails, an angle iron rail, a rolled tubular construction or other special configuration. Accordingly, in this aspect of the present invention, a specially shaped and configured slide end of the universal cross member is used and which has normal holes to enable the user to use screws to fasten the slide end to a wooden side rail or, as another alternative, the slide end has a shape that enables it to be easily snapped into a rail connector that is also specially configured to receive the slide end. That rail connector can be a plastic molded part and which also has the versatility to be affixed to a steel angle iron side rail or custom roll formed metal rail by means of metal clips or to be insert into a gouged portion of a wooden side rail, or even be installed on an existing roll formed rail constructed in accordance with U.S. Pat. No. 4,745,644 of Pottschmidt. Further, the rail connector can be factory installed by the manufacturer as a fixed part of the side rail or, can be installed by the person setting up the bed.
In the preferred embodiment, the slide end is simply snapped into the rail connection and thus can be readily installed by a person setting up the bed without the need for any tools such that the time required for assembly of the bed is greatly reduced and can be carried out by the user in the home. The actual connection between the slide connector and the rail connector is preferably such that the snap-in procedure is simple to join those components together, without the use of any tools, however, the completed connection cannot easily be detached so that the connection is sure and positive and, preferably, cannot be disconnected without the use of tools. Thus, once installed, the universal cross member of the present invention is solidly affixed to the particular side rail and is not easily dislodged but can only be removed by quite deliberate positive action by the user. As such, no tools are necessary to carry out the assembly of the bed when the rail connector of the present invention is installed on the side rails.